if the shoe fits
by quillquate
Summary: In which Tsuna discovers that biting people to death is an amazing way to stop people from picking on him.
1. Chapter 1

Tsuna is seven-years-old when he first hears rumors about Hibari Kyouya. "He's a monster," they say. "He'll even kick kittens!" a girl adds. He's not sure they're _true_ , but one thing he knows for sure is that a) Hibari Kyouya exists and b) he likes violence. A lot.

He learns this when he is backed up against a wall, Shinji looming over him. "Lunch money," Shinji orders, thrusting a hand out. "Come on, Dame-Tsuna, I know you have some spare change. Give it here, or _else_." Tsuna squeaks and murmurs incomprehensibly. "Ha? What did you say?"

"I don't have any!" he sniffles. Earnest brown eyes glimmer with unshed tears as he says, "I forgot it on the kitchen table this morning, I don't have any money!"

"I know you're lying, don't make me sic Hibari on you!"

"H-Hibari?"

Shinji sneers unpleasantly. "Don't you know? He punishes people who break the rules. All I have to do is tip him off about you disturbing the peace and boom! You're a dead man walking. You'll be bitten to death! And no one can save you since everybody's scared of him." He looks remarkably pleased about his genius plan, rubbing his hands together like a stereotypical villain.

"But I'm not doing anything!" Tsuna protests weakly.

"You're infecting Namimori with your patheticness, that's reason enough. And I heard that Hibari _hates_ stuff like that. Anyways, lunch money! Give!"

Tsuna frantically looks around for an escape route, but to no avail. Shinji looks about ready to sock him on the face so he doubts that he can talk it out. _Well,_ Tsuna reasons, _if it works for him..?_ He clenches a fist, stops his legs from shaking, and looks at Shinji straight in the eyes. Unbeknownst to Tsuna, orange flickers in his eyes as he thinks, _I'm tired of being scared!_ and leaps forward to attack.

By biting Shinji on the shoulder.

XXXXXXXXXX

"Man, what's up with your shoulder?" Mochida asks, punching Shinji lightly. "Did a rabid squirrel get you?"

"I don't want to talk about it," Shinji replies sourly.

XXXXXXXXXX

Tsuna discovers that biting people is an _amazing_ way to stop people from picking on him. They tend to steer clear of him nowadays, and it feels good. It's a bit lonely, he supposes, but he's used to it. He bares his teeth at Shinji who flinches as he passes by.

Yeah. Life is good.

Meanwhile, the teachers at Namimori are panicking and asking themselves how Dame-Tsuna became so...vicious. "He was always useless, but at least he was respectful!" the principal moans, throwing his hands up in despair. "Now, it's like...it's like he's being possessed by a demon!"

"Should we call a priest?" Nezu asks anxiously, being a victim of Tsuna's teeth. The principal gives a helpless shrug. The secretary nods solemnly and picks up the phone.

Needless to say, Tsuna did _not_ appreciate being drenched by holy water. The priest got 400 yen and a bite to his arm for his troubles. He also got a trip to the hospital.

(He had to get thirteen stitches.)

XXXXXXXXXXX

Tsuna lets out a little sigh as he is cornered by a group of older kids. "People say that you're scary," says one, peering at Tsuna. "But we know better! You're still weak, pathetic, and spineless. And I _know_ we can take you on." He regards the bully with blank eyes. "Don't stare at me like that, weirdo! Get him, guys-agh! Get off my arm, you little freak. Get off, get off, get off!"

Tsuna latches his jaw tight around the appendage, refusing to let go. The familiar taste of blood fills his mouth as the boy hollers. The rest of the group are staring at them, slack-jawed.

"Why are you herbivores crowding?" a voice interrupts. Tsuna looks up to see gray eyes observing him quietly. "...What are you doing."

"Mhating dem to dahs," Tsuna says into skin. He lets go as the arm suddenly goes slack. "I think he fainted."

"You better sleep with one eye open, we'll get you for this!" The group plus an unconscious boy zooms away like fire is licking at their heels.

"Not bad," the boy says with approval laced in his words. Not that Tsuna notices, because the first thing he notices are tonfas hidden inside the boy's jacket and his intuition blaring danger.

He does the first thing that comes into this mind.

"Herbivore, if you don't get off me, I will bite you to death."

"Herbivore, my arm is bleeding."

"...Did you just fall asleep?"

* * *

 **A/N:** Prompt from Tumblr by katekyo-hitman-aus. I'll mark this as complete for now, but don't be surprised if I add on to this.


	2. Chapter 2

Reborn frowns. He had dropped the flyer for his tortu- _tutoring_ and he still hadn't received a call. _Perhaps she got it,_ he thinks, _but she forgot to respond. That fits Iemitsu's description of a ditzy wife. Yes, that's probably what happened. I should go directly to the Sawada's and get this cleared up._

He's at their front step five minutes later, using secret routes and tunnels that only Reborn knows about. He rings the doorbell and waits patiently. The door opens to reveal a plain-looking housewife. _This must be Nana._ "Oh, dear. Are you lost?" Nana asks, wiping her hands on her apron.

"I'm the home tutor, Reborn."

She puts a hand to her face. "From that flyer? Well, I didn't know you would be coming here, I didn't sign up for your services, after all." _She didn't want it in the first place?_ Reborn thinks. _Unexpected, but I can work with that. I'm not the Greatest Hitman in the World for no reason, after all._

"Oh, but I was sent by your husband, Iemitsu. You see, he was worried about how his family was doing, and I volunteered to go and visit. He also mentioned that your son, Tsuna, struggled in academics so I kindly offered to help in that area as well," Reborn says with a charming smile.

"Well, if you put it that way…" Nana trails off. "Tsu-kun isn't home yet, but you can come inside and wait. He usually gets back around five."

He's seated in a plushy sofa along with a freshly brewed cup of tea. He prefers espresso, but he supposes that this will do. No need to be rude to a lady who has nothing to do with the criminal world. Reborn scans the room, looking for any clues as to what Sawada is doing this late. Curiously enough, there's signs of cracked furniture and - is that blood on the counter? It _could_ be Sawada's apparent clumsiness…

"You see," Nana begins, sitting across from him, "as long as Tsu-kun is happy, I'm not too concerned about his grades. He used to be bullied a lot. He would come home every day with bruises and all that. He insisted that he just tripped, but I knew better than that."

"Used to?"

Nana brightens up, her smile radiating flowers and sparkles. "He made a friend! Maybe you know him, he's famous around here. Hibari Kyouya? Kyou-kun has been helping Tsu-kun defend himself from those mean bullies!" At this point, she mimes a punch. "Boom! It makes me so happy that my son finally got a friend!"

 _Hibari Kyouya,_ Reborn muses. _Son of deceased police officers, known for keeping the peace in Namimori. How did someone with the nickname of 'Tuna-fish' get the attention of someone like that?_ He snaps his attention back to Nana when she says, "It seems like he's getting into a lot of trouble recently, though. The accusations are kind of funny, they're saying that my sweet Tsu-kun has been _biting_ people! Can you imagine that?"

XXXXXXXXXX

Yes, Reborn can imagine that. It might have something to do with Sawada lunging at him with lightning speed, mouth wide open. He immediately leaps away, of course. He's not going to be bit by some pipsqueak of a brat. He kicks Sawada on the head, knocking the brat out.

He has to leap back _again_ when a black blur rushes at him, tonfas extended. _So. This is the infamous Hibari Kyouya,_ he thinks as he weaves between blows. Somehow, Nana hasn't come to check on the commotion at her front door.

"Quit it," he orders, bopping Hibari on the head.

The boy snarls and says, "He fainted."

"Don't be so melodramatic." Reborn rolls his eyes. _Kids._ Nevermind that he is currently in the body of an infant. "...You still here?" Hibari huffs and regards him silently. Reborn almost laughs at the pitiful attempt of emitting killing intent. He doesn't, but it takes a will of iron to resist.

Ten minutes later, Sawada is awake and looks at Reborn with a sense of respect. He preens inwardly. Damn brats these days didn't know how to give him proper _respect._ It's nice to be treated how you're supposed to be treated.

Eyes shining, Sawada goes, "That's a-amazing! I was knocked out just like that!"

"Why do you sound so happy?" Hibari asks, disgruntled.

"Because that means he's even stronger than you, Carnivore-senpai!" And _wow_ , did Sawada actually go around calling the Hibari kid "Carnivore-senpai?" Hibari turns his head away. It's obvious that he's sulking but not trying to show it, but Reborn can read his body language well enough.

"I'm from the mafia. Sawada Tsunayoshi is to become the head of the Vongola, the most prosperous mafia family there is."

"That's great..?" Sawada says uncertainly.

"It is, you should be honored to be the heir," Reborn agrees.

Sawada pales rapidly. "This is a joke, right? Even if I'm a bit stronger now, I can't - I can't just be a criminal!"

"Mafia," Reborn corrects.

"You don't have to do whatever you don't want to do," Hibari puts in. "I can always beat them up for you."

"Thanks," Sawada replies, looking touched. Hibari gives a short nod and strides into the kitchen like he owns the damn place.

"Unfortunately for you and not for me, the only answer is yes," Reborn says. "Let me phrase my earlier response. You're the _only_ heir. You really don't have a choice."

When Sawada lets out a screech of dismay, Reborn can kind of see why Iemitsu rants about his son's 'unmanliness.' At least he knew how to defend himself, even though the method is a little unhygienic.


End file.
